Storey's estimator for the proportion of true null hypotheses, originally proposed under the continuous framework, has been modified in this work under the discrete framework. The modification results in improved estimation of the parameter of interest. The proposed estimator is used to formulate an adaptive version of the Benjamini-Hochberg procedure.
View Article and Find Full Text PDFThe receptor binding domain (RBD) of SARS-CoV-2 is the primary target of neutralizing antibodies. We have previously reported the design and characterization of a mammalian cell expressed RBD derivative, mRBD1-3.2, that has higher thermal stability and greatly enhanced immunogenicity relative to the wild type mRBD.
View Article and Find Full Text PDFIn order to adapt in host tissues, microbial pathogens regulate their gene expression through a variety of transcription factors. Here, we have functionally characterized Rv0792c, a HutC homolog from Mycobacterium tuberculosis. In comparison to the parental strain, a strain of M.
View Article and Find Full Text PDFRegulation of biological processes by proteins often involves the formation of transient, multimeric complexes whose characterization is mechanistically important but challenging. The bacterial toxin CcdB binds and poisons DNA Gyrase. The corresponding antitoxin CcdA extracts CcdB from its complex with Gyrase through the formation of a transient ternary complex, thus rejuvenating Gyrase.
View Article and Find Full Text PDFThe genome harbours nine toxin-antitoxin (TA) systems of the mazEF family. These consist of two proteins, a toxin and an antitoxin, encoded in an operon. While the toxin has a conserved fold, the antitoxins are structurally diverse and the toxin binding region is typically intrinsically disordered before binding.
View Article and Find Full Text PDFMost amino acid substitutions in a protein either lead to partial loss-of-function or are near neutral. Several studies have shown the existence of second-site mutations that can rescue defects caused by diverse loss-of-function mutations. Such global suppressor mutations are key drivers of protein evolution.
View Article and Find Full Text PDFThe Mycobacterium tuberculosis genome harbors nine toxin-antitoxin (TA) systems that are members of the family, unlike other prokaryotes, which have only one or two. Although the overall tertiary folds of MazF toxins are predicted to be similar, it is unclear how they recognize structurally different RNAs and antitoxins with divergent sequence specificity. Here, we have expressed and purified the individual components and complex of the MazEF6 TA system from M.
View Article and Find Full Text PDFAlthough there have been recent transformative advances in the area of protein structure prediction, prediction of point mutations that improve protein stability remains challenging. It is possible to construct and screen large mutant libraries for improved activity or ligand binding. However, reliable screens for mutants that improve protein stability do not yet exist, especially for proteins that are well folded and relatively stable.
View Article and Find Full Text PDFharbours nine toxin-antitoxin (TA) systems of the MazEF family. MazEF TA modules are of immense importance due to the perceived role of the MazF toxin in persistence and disease. The MazE antitoxin has a disordered C-terminal domain that binds the toxin, MazF and neutralizes its endoribonuclease activity.
View Article and Find Full Text PDFTwo recently introduced model-based bias-corrected estimators for proportion of true null hypotheses ( ) under multiple hypotheses testing scenario have been restructured for random observations under a suitable failure model, available for each of the common hypotheses. Based on stochastic ordering, a new motivation behind formulation of some related estimators for is given. The reduction of bias for the model-based estimators are theoretically justified and algorithms for computing the estimators are also presented.
View Article and Find Full Text PDFThe prokaryotic ubiquitous Toxin-antitoxin (TA) modules encodes for a stable toxin and an unstable antitoxin. VapBC subfamily is the most abundant Type II TA system in genome. However, the exact physiological role for most of these Type II TA systems are still unknown.
View Article and Find Full Text PDFMost biological processes involve formation of transient complexes where binding of a ligand allosterically modulates function. The ccd toxin-antitoxin system is involved in plasmid maintenance and bacterial persistence. The CcdA antitoxin accelerates dissociation of CcdB from its complex with DNA gyrase, binds and neutralizes CcdB, but the mechanistic details are unclear.
View Article and Find Full Text PDFWith advancements in high-throughput generation of phenotypic data on mutant proteins, it has become important to individually characterize different proteins or their variants rapidly and with minimal sample consumption. We have made use of a nano differential scanning fluorimetric device, from NanoTemper technologies, to rapidly carry out isothermal chemical denaturation and measure folding/unfolding kinetics of proteins and compared these to corresponding data obtained from conventional spectrofluorimetry. We show that using sample volumes 10-50-fold lower than with conventional fluorimetric techniques, one can rapidly and accurately measure thermodynamic and kinetic stability, as well as folding/unfolding kinetics.
View Article and Find Full Text PDFAlthough high-resistivity, low-loss silicon is an excellent material for terahertz transmission optics, its high refractive index necessitates an antireflection treatment. We fabricated a wide-bandwidth, two-layer antireflection treatment by cutting subwavelength structures into the silicon surface using multi-depth deep reactive-ion etching (DRIE). A wafer with this treatment on both sides has <-20 dB (<1%) reflectance over 187-317 GHz at a 15° angle of incidence in TE polarization.
View Article and Find Full Text PDFThe problem of testing equality of means of a bivariate normal distribution on the basis of a sample of size n has been considered when the labels of the observations are either missing or not known. The problem may arise in many applied settings, especially in genetics. Classical likelihood ratio test fails here because of identifiability problems.
View Article and Find Full Text PDFAim Of The Study: Delayed hemorrhage, though rare, remains a significant source of morbidity and mortality after pancreaticoduodenectomy (PD). An important cause of this delayed hemorrhage is erosion or pseudoaneurysm formation of the gastroduodenal artery (GDA) by pancreatic enzymes and adjacent intra-abdominal sepsis. So protection of the GDA stump may avoid this devastating complication.
View Article and Find Full Text PDFBackground: There is paucity of literature regarding the Frey procedure for children with chronic pancreatitis. The purpose of this study is to present our experience with the Frey procedure in children.
Methods: This is an observational retrospective review study.
An on-chip lectin microarray based glycomic approach is employed to identify glyco markers for different gastritis and gastric cancer. Changes in protein glycosylation have impact on biological function and carcinogenesis. These altered glycosylation patterns in serum proteins and membrane proteins of tumor cells can be unique markers of cancer progression and hence have been exploited to diagnose various stages of cancer through lectin microarray technology.
View Article and Find Full Text PDFScientific formalizations of the notion of growth and measurement of the rate of growth in living organisms are age-old problems. The most frequently used metric, "Average Relative Growth Rate" is invariant under the choice of the underlying growth model. Theoretically, the estimated rate parameter and relative growth rate remain constant for all mutually exclusive and exhaustive time intervals if the underlying law is exponential but not for other common growth laws (e.
View Article and Find Full Text PDFMalrotation of gut is a congenital anomaly and patients usually present in childhood. Occasionally it may present in adulthood. Patients are usually asymptomatic when malrotation of gut is detected during investigations or operation.
View Article and Find Full Text PDFFoxp3(+) T regulatory cells (Tregs) are critically important for the maintenance of immunological tolerance, immune homeostasis, and prevention of autoimmunity. Dendritic cells (DCs) are one of the major targets of Treg-mediated suppression. Some studies have suggested that Treg-mediated suppression of DC function is mediated by the interaction of CTLA-4 on Tregs with CD80/CD86 on the DCs resulting in downregulation of CD80/CD86 expression and a decrease in costimulation.
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